jenkins



UNITED STATES PATENT OFFICE.

JOSEPH H. JENKINS, OF SMITHVILLE, MISSOURI, ASSIGNOR TO HIMSELF AND ELIJA-IH W. JENKINS, OF SAME PLACE.

SAWMILL.

Specification of Letters Patent No. 27,021, dated January 31, 1860.

To all 'whom it may concern:

Be it known that I, JOSEPH H. JnNxiNs, of Smithville, in the county of Clay and `State of Missouri, have invented a new several gures indicate corresponding parts.,

My invent-ion consists in the arrangement hereinafter described whereby the saw, although it is thrown off from the log and made to assume an inclined position as it ascends, it is brought against the log and made to retain a perpendicular or nearly perpendicular position while it is descend- I-Ieretofore I believe in saw-mills, this end has not been attained, because the eccentrics which are used to pitch the saw from and toward the log have not been combined with a controlling or compensating frame such as I use, and they consequently being allowed to incline the saw just as much in its descending movement as they are allowed to incline it in its ascending movement. It is desirable to have the saw inclined as it rises in order to clear the log, but it is not desirable to have it inclined as it descends, because if it is inclined at this stage of the operation, the saw will not come in contact with the log until considerable of its lower portion has passed down below the log and thus the action of said portion of the saw on the log, lost.

To enable others, skilled in the art, to make and use my invention, I will proceed to describe its construction and operation.

A, represents the frame of the saw-mill B, the sash, and C, the saw of the same. The sash moves up and down in grooves a, a, which are a little wider than the guides vof the sash so as to allow the sash a chance to play horizontally to a slight extent as it moves from and toward the log. D, is the driving shaft. E, E, ordinary eccentrics arranged on the same, and F, F, )itmen leading from the eccentrics up to the top of the sash.

Gr, is an auxiliary eccentric set diametrically opposite to the eccentrics E, on the driving shaft D. I-I, is an auxiliary pitman.

The eccentrics E, and pitmans F, give the up and down motions to the saw sash while the eccentric G, and pitman H, would, in addition to the outward movement from the log and inclined position which/ it iinpaits to the same in its ascent, not only give an inward movement, but a very considerable inclination to the saw as it descends, if it were not for the interposition of the following described arrangement:

I, is a rocking shaft provided with an arm J, on its underside and two arms K, K, on its upper side. This shaft is connected by its lower arm and the pitman I-I, with the auxiliary eccentric G, and with the lower end of the saw sash by means of the upper arms K, K, and a hinged swinging frame L, L, as represented. By thus interposing the device just described, the saw sash in its ascent is pitched back from the log and caused to incline as represented in black, and in its descent is allowed to pitch sufficiently forward to assume a perpendicular position, as illustrated in red, and is then arrested and compelled to descend in nearly a vertical position. The arm J, is made longer than those K, and holes g, g, are provided in the same so that the saw may be caused to move from the log to a greater or less extent; and also that the saw may be caused to descend slightly inclining if desirable. The above described operation of the saw, results from the auxiliary eccentric being set so as to force the lower arm of the rock shaft to the position shown in black as the saw ascends, and to pull it forward to the position shown in red just as the saw begins to descend and to partially cease acting on it until the saw has completed its down stroke and is about to commence its up stroke; the partial cessation of the action of the eccentric results from the counteracting effect of the upper swinging frame K, K, to the lower pitman II, which edect, although positive does not interfere with the revolution of the eccentric G, because the pitman IFI, has freedom to turn on its point of connection d, and consequently, although lifted I at its end e, it does not force out the arm J, of the rock shaft or interfere with the slight outward movement given to arms K, K, While the swinging frame is assuming a horizontal position, until the saw has nearly completed its down stroke at which stage of the operation the eccentric begins again t0 force the lower arm of the rock-shaft outward; this being possible owing to the upper swinging frame having descended below the horizontal line and assumed an inclined position, in which position it ceases momentarily to act positively in opposition to the lower` arm of the rock shaft.

What I claim as my invention and desire t0 secure by Letters Patent is f The employment of the armed rock shaft I, pitman H, eccentric G,'and hinged swinging frame L, in combination with a reciprocating saw sash in the manner and for the purpose herein described.

The above specification of my improve- Vment in saw mills signed my me this 8th day 0i December, 1859.

JOSEPH H. JENKINS.

Witnesses:

GOODWIN Y. AT LEE, R. W'. FENWICK. 

